package hu;

import java.util.*;

/**
 * 动态规划问题
 * 编辑距离
 */
public class hu52 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String s1 = sc.nextLine();
        String s2 = sc.nextLine();
        int m = s1.length();
        int n = s2.length();
        int[][] dp = new int[m + 1][n + 1];
        for (int i = 0; i <= m; i++) {
            dp[i][0] = i;
        }
        for (int i = 0; i <= n; i++) {
            dp[0][i] = i;
        }
        for (int i = 1; i <= m; i++) {
            for (int j = 1; j <= n; j++) {
                if(s1.charAt(i - 1) == s2.charAt(j - 1))
                    dp[i][j] = dp[i - 1][j - 1];
                else{
                    dp[i][j] = Math.min(Math.min(dp[i -1][j], dp[i][j - 1]), dp[i - 1][j - 1]) + 1;
                }
            }
        }
        System.out.println(dp[m][n]);
    }
}
